HTTP 404 Not Found

What it means

Not Found describes how the server processed the request and what the client should do next.

Why it happens

Common triggers include protocol conditions, routing decisions, and application behavior.

Common causes

• Broken internal link
• Deleted page
• Incorrect URL
• Routing mismatch
• Missing rewrite rule

How to fix it

• Verify the URL
• Restore the resource if it was removed unintentionally
• Add or correct server routing
• Set up a redirect if the page moved
• Update internal links

Example request/response

GET /missing-page HTTP/1.1
Host: errorlookup.com

HTTP/1.1 404 Not Found
Content-Type: text/html

Browser/dev/server context

Use browser network tools, server logs, and APM traces together when diagnosing HTTP 404.

Related status codes

FAQ

Does 404 mean the server is down?

No. It means the resource was not found at that URL.

Should I redirect all 404 pages?

Only when there is a relevant replacement resource.